Bump cutter with means for reducing effect of bumps



Aug. 17, 1965 c. w. HATCHER BUMP CUTTER WITH MEANS FOR REDUCING EFFECT OF BUMPS Filed April 11, 1963 3 Sheets-Sheet l INVENTOR CECIL W. HATCHER ATTORNEY 1965 c. w. HATCHER 3,201,173

BUMP CUTTER WITH MEANS FOR REDUCING EFFECT OF BUMPS Filed April 11, 1963 z Sheets-Sheet 2 86 5J3 249 I 1 ai mqmra WW!!! Hi "MIKE 11 f f 1 /2 s4 47 48 iiiii i I 72 79 l g l 1 MUM l .I 1:; xvl 1 -55 MI I V V I CECIL W. HATCHER INVENTOR w BY I ATTORNEY Aug. 17, 1965 C. W. HATCH ER BUMP CUTTER WITH MEANS FOR REDUCING EFFECT OF BUMPS Filed April 11, 1963 3 Sheets-$heet 3 .lfl]

RESERVOIR HYD.

lo'ToR BOX CECIL W. HATCHER INVENTOR ATTORNEY United States Patent 4 Claims. (Cl. 299-39 The invention relates to a pavement-leveling machine or bump cutter with means for reducing the effect of bumps and, more particularly, it relates to a self-pro pelled vehicle having intermediate front and rear wheel means thereon, a rotary cutter for removing bumps from concrete paving, such as aircraft landing fields, floors and the like.

The invention is an improvement on the bump cutters disclosed and claimed in my Patent No. 3,007,687, issued November 7, 1961, and in my Patent No. 3,037,755, issued Iune 5, 1962.

In my Patent No. 3,007,687, the sensitivity of the machine to relatively minor irregularities of the surface of the paving is reduced by supporting the cutter, for height adjustment, on an elongated frame or frame means having its front wheel means at a longer distance from the cutter than its rear wheel means whereby the variation in the height of the cutter is only a fraction of the variation in the height of the front end of such elongated frame means as its front wheel means rides over the paving.

My Patent No. 3,037,755 is directed to an arrangement wherein the rear of the frame means is pivotally connected to a truck having front and rear driving wheels, the truck thus acting to reduce the vertical motion at the rear of the frame means in proportion to the lever arms between the front and rear wheels of the truck and the truck pivot.

For reasons explained in my aforementioned patents, it is important to reduce the error in the height of the cutter following the action of the front wheel means, noting that while the location of the front wheel means reduces the error, it does not eliminate it, for the reason that such error is reflected into the action of the rear Wheel means to cause a further error in the height of the cutter. In other words, the accuracy with which the height of the cutter is maintained depends on the combined action of both the front and rear wheel supports.

The present invention has for an object to further improve the accuracy with which the level of the cutter is maintained. This is accomplished by providing an improved bump reducing support for the front wheel means. My co-pending application Serial No. 150,039, filed November 3, 1961, of which the present application is a division, discloses and claims the feature of providing an improved rear wheel suspension wherein a bump at one side of the machine is not reflected into the undesired movement of the other side of the machine, the Width of the cutter head being preferably greater than the width of the rear wheel means to provide a relatively level path therefor.

For further details of the invention, reference may be made to the drawings wherein:

FIG. 1 is a view in side elevation of a bump cutter according to the present invention;

FIG. 2 is an enlarged sectional view on line 2;-2 of FIG. 1;

FIG. 3 is a sectional view on line 3-3 of FIG. 2;

FIG. 4 is an enlarged sectional view on line 4-4 of FIG. 1;

FIG. 5 is a sectional view on line 5-5 of FIG. 4; and

FIG. 6 is a flow diagram of the hydraulic control mechanism employed in connection with the invention.

EgZhLli/B Patented Aug. 17, lhfi ice Referring in detail to the drawings, the vehicle 1 has frame means including a vehicle frame 2 at the front end of which is rotatably mounted a cutter head 3 on a transverse horizontal cutter shaft 4 having a pulley 5 connected by belt 6 to the pulley 7 on the engine 8. Cutter head 3 comprises a series of abrasive discs on the cutter shaft with separators'for leaving a series of ridges in the pavement, or the abrasive discs may be spaced close enough to make a substantially smooth cut. The engine 8 as shown at 9 is mounted on the rear end of an extension frame Ill forming part of the aforementioned frame means. Extension frame ill as shown in FIG. 2 has opposite arms 11 and 312, being somewhat U-shaped. The rear end of the extension frame It has a hinge connection on a transverse horizontal axis, as shown at 13, with an upright post 14 at each side of the vehicle frame 2, one of these posts being shown in FIG. 1 at 14. i

The front end of extension frame 10 has a hinge connection 15 on a transverse horizontal axis with the front wheel frame or truck 16 of a front wheel means which has a rear caster wheel 17 and a front wheel 18 for steering. The hinge connection 15 includes suitable bearings 19 on the frame it), the bearing 20 on the truck 16 and a hinge pin or shaft 21.

The steerable front wheel 18 has an axle 22, see FIG. 3, carried by a bracket 23 fixed to a vertical shaft 24 having a bearing 25 on the body 26 of the truck and a further bearing 27 in a housing 28 fixed to the body 26.

The shaft 24 at its upper end has a worm wheel 29 meshing with a worm 3t rotatably supported on a horizontal axis by bearings 31 and 32 carried by the casing 28. The worm 30 is connected by a universal coupling 33 to a short steering rod section 34, the latter having a connection through the universal coupling 35 with the front end of the inclined steering rod 36. Steering rod 36 has bearing supports on the extension frame 10 as indicated at 37, 38 and 39. Bearing 39 is a self aligning bearing having a swivel mount to permit steering rod 36 to pivot about hinge 13 while the steering rod is supported from vehicle frame 2 by bearing 39. The rear end of extension rod 36 has a handle or steering wheel 40 accessible to an operator for whom a seat 41 is provided, this seat being mounted as shown at 4-2 on the vehicle frame 2.

As the front of the extension frame 10, which determines the height of the cutter head 3 as described later, is mounted by the hinge connection 15 at an intermediate point on the front truck in, any bump encountered during the forward travel of the front wheels 17 and 13 will be reduced in its effect on the extension frame 10 in proportion to the relative distances involved between the hinge connection 15 and the wheels 17 and 18.

The effect of bumps at the rear of the machine during its forward travel, is reduced as follows:

The rear of the vehicle frame 2 is supported by a rear wheel means comprising a truck 43 which is composed of two truck members 44 and 45 arranged side by side, see FIG. 4.

Truck member 45 has front and rear driven wheels 46 and 47 having axles 48 and 49 having bearing supports 51, 52 and 53, 54 on the truck frame 55. Axle 48 has a sprocket 56 and axle 49 has a sprocket 5'7. Similarly, the other truck member 44 has a truck frame 53 having bearings 59 and (it? for axle 61 of rear driven wheel 62. Also, truck frame 58 has bearings 63, 64 for the axle of front driven wheel 66. Axle ell has a sprocket 67 and axle 65 has a sprocket 68.

A drive shaft 70 extends across the middle of both of the truck members 44 and 45 having a sprocket 71 connected by chain 72 to sprocket 5s, also having a sprocket 78 connected by chain 74 to sprocket 57 also having a sprocket 7:; connected by a chain 76 to sprocket 68, a sprocket 77 connected by chain 78 to sprocket 6'7, and a central sprocket 7 9 connected by chain 88, see FIGS. 1 and 4, to a gear box 81, see FIGS. 1 and 6, which is driven by the hydraulic motor 82.

In FIG. 4, the line 113 shows that the width of the cutter head 3 in an axial direction is greater, viz., 24 inches, than the width to the outside edges of the wheels of truck 43, viz., 23 inches. The wheels of the truck 43 thus ride on the path cut by the cutter head 3.

The vehicle frame 2 has laterally spaced side arms 83 and 84, see FIG. 4, the rear ends of which are supported by bearings 85 and 86 on the opposite ends 87 and 88 of the drive shaft 70 which thus serves as a hinge connection for the rear end of the vehicle frame 2, at a horizonal axis intermediate the front and rear wheels of the truck members 44 and 45, the latter being pivoted on the drive shaft by means of the bearings shown in FIG. 4. Both the hinge connection just described for the rear end of Vehicle frame 2 and the use of individual truck members 44 and 45 contribute to reducing the effect on the cutter head 3 of bumps encountered by the rear truck 43 as the vehicle moves in a forward direction.

As shown in FIG. 1, a hydraulic cylinder 98, see also FIG. 6, has a hinge connection 91 with the extension frame 16, and having a piston 92 and plunger 93 having a hinge connection 94- with a U shaped bracket 95, which has opposite vertical arms connected to the front end of the arms 83 and 84 of the vehicle frame 2, one of these arms 86 which arises from the front arm 83 which appears in FIG. 1. Also, the bracket 95 has an adjustable stop 97 to limit the downward movement of, and determine the height of the cutter head 3. As described in connection with FIG. 6, means are provided for supplying hydraulic pressure to the opposite ends of cylinder 98, to either raise the cutter head 3, or to use the weight of engine 8 as a buttress to snub the cutter head 3 and hold it to its work.

Turning to FIG. 6 of the drawings, diagrammatically illustrated therein is a hydraulic system which, considered generally, includes a reservoir 98, a hand pump 99 for delivering fluid to one end of the cylinder 98 to snub the cutter head 3 down in engagement with the pavement, a gear pump 185 having its inlet connected to the reservoir, a two-way valve 106 for delivering fluid from the pump 1% to the other end of the cylinder 90 through conduit 118 to lift the cutter head clear of the pavement, a threeway valve 109 for delivering fluid from the pump 1% to the hydraulic motor 82 through conduits 123 or 124, selectively, to drive the motor in one direction or the other to cause it to drive the vehicle 1 forwardly or rearwardly, and an adjustable relief valve 112 for controlling the fluid pressure of fluid to the hydraulic motor 82 irrespective of the direction in which it is driven. Fluid dumped by relief valve 112 flows through the conduit extending downwardly therefrom to conduit 121 and back to reservoir 98. The hand pump 95 and the valves 1%, 189 and 112 are so located that they are readily accessible from the operators seat 41.

' Considering the hydraulic system in more detail, the hand pump 99 is of the reciprocating type and includes a plunger 113 reciprocable by a pivoted handle 188, the cylinder, not shown, in which the plunger 113 is reciprocable being provided with an inlet check valve, not shown, which communicates with the reservoir 98 through a line 1841, and being equipped with an outlet check valve, not shown, which communicates through a line 101 with a snubber port 1112 adjacent the upper end of the cylinder )8. Manual operation of the pump 99 delivers fluid from the reservoir 98 to the cylinder 96 above the piston 92 through the lines 104- and 1111 to snub the cutter head 3 downwardly against the pavement. The outlet check valve associated with the plunger 113 locks the cutter head 3 in its snubbed condition. As will be apparent, snubbing the cutter head 3 in this manner 4. locks the vehicle and extension frames 2 and 10 together, and makes them in effect a single rigid frame, to apply the maximum possible weight to the cutter head 3 to maintain it in engagement with the pavement without chattering.

When it is desired to release the snubbing action, a relief valve 183 is opened to connect the line 101 to lines 114 and 115 leading to the reservoir 98.

The valve 1% is operated by a handle 107. When it is in one position, other than neutral, it delivers fluid to a line 118 leading to a cutter head lifting port 188. When it is desired to lower the cutter head 3, relief valve 119 is opened and fluid is returned to the reservoir 98 by way of lines 118, 121), 121, 111 and 115. When the valve 106 is in its neutral position, it permits fluid from the pump 105 to flow to the valve 112 and to the valve 109.

The valve 189 is a three-way valve operable by a handle 110. When the valve 1119 is in a neutral position, it receives fluid from the pump 105 through the line 116, and returns it to the reservoir 98 through a line 122 and the lines 111 and 115. Under such conditions, the hydraulic motor 82 is inoperative and the vehicle 1 is stationary.

To drive the vehicle 1 in the forward direction, the valve 109 is placed in an operating position such that fluid under pressure from the pump 1115 is delivered to one side of the hydraulic motor 82 through a line 123, the spent fluid being returned to the reservoir through a line 124 and the lines 122, 111 and 115. Conversely, when it is desired to propel the vehicle 1 in the reverse direction, the valve 109 is set in a position to deliver fluid under pressure from the pump 105 to the opposite side of the hydraulic motor 82 through the line 124. Under such conditions, spent fluid is returned to the reservoir through the lines 123, 122, 111 and 115.

I claim:

1. In a self-propelled, vehicle-type, pavement-leveling machine, the combination of:

(a) frame means having longitudinally spaced front and rear ends;

(b) front wheel means connected to and supporting said frame means adjacent said front end thereof;

(0) rear wheel means connected to and supporting said frame means adjacent said rear end thereof;

((1) rotary cutter means mounted on said frame means intermediate said front wheel means and said rear wheel means, and rotatable about a horizontal axis extending transversely of said frame means, for leveling pavement over which the machine runs;

(e) means on said frame means and connected to said rotary cutter means and said rear wheel means for driving said rotary cutter means and said rear wheel means;

(f) said rotary cutter means being spaced forwardly from said rear wheel means a first longitudinal dis- 7 tance, and said front wheel means being spaced forwardly from said rotary cutter means a second longitudinal distance which is large as compared to said first longitudinal distance, so that any tendency of bumps encountered by said front wheel means to move said rotary cutter means vertically is reduced in proportion to the ratio of said first longitudinal distance to said second longitudinal distance;

(g) said front wheel means including a front wheel frame having tandem front wheels rotatably mounted thereon; and

(h) said front wheel frame being pivotally connected to said frame means for pivotal movement relative thereto about a transverse horizontal axis intermediate said tandem front wheels, so as to further reduce any tendency of bumps encountered by said front wheel means to move said rotary cutter means vertically.

machine, the combination of:

(a) frame means having longitudinally spaced front and rear ends;

(b) front wheel means connected to and supporting said frame means adjacent said front end thereof; rear Wheel means connected to and supporting said frame means adjacent said rear end thereof;

(d) rotary cutter means mounted on said frame means intermediate said front wheel means and said rear Wheel means, and rotatable about a horizontal axis extending transversely of said frame means, for leveling pavement over which the machine runs;

(e) means on said frame means and connected to said rotary cutter means and said rear wheel means for driving said rotary cutter means and said rear wheel means;

(f) said rotary cutter means being spaced forwardly from said rear wheel means a first longitudinal distance, and said front wheel means being spaced forwardly from said rotary cutter means a second longitudinal distance which is large as compared to said first longitudinal distance, so that any tendency of bumps encountered by said front wheel means to move said rotary cutter means vertically is reduced in proportion to the ratio of said first longitudinal distance to said second longitudinal distance;

(g) said front wheel means including a front wheel frame having tandem front wheels rotatably mounted thereon;

(h) said front wheel frame being pivotally connected to said frame means for pivotal movement relative thereto about a transverse horizontal axis intermediate said tandem front wheels, so as to further reduce any tendency of bumps encountered by said front wheel means to move said rotary cutter means vertically;

(i) one of said front wheels being a steerable wheel and the other being a caster Wheel; and

(j) means for steering said steerable wheel.

3. In a self-propelled, vehicle-type, pavement-leveling machine, the combination of:

(a) frame means having longitudinally spaced front and rear ends;

(b) front wheel means connected to and supporting said frame means adjacent said front end thereof; (0) rear wheel means connected to and supporting said frame means adjacent said rear end thereof;

(d) rotary cutter means mounted on said frame means intermediate said front Wheel means and said rear wheel means, and rotatable about a horizontal axis extending transversely of said frame means, for leveling pavement over which the machine runs;

(e) means on said frame means and connected to said rotary cutter means and said rear wheel means for driving said rotary cutter means and said rear wheel means;

d (f) said rotary cutter means being spaced forwardly from said rear wheel means a first longitudinal distance, and said front wheel means being spaced forwardly from said rotary cutter means a second lon- 5 gitudinal distance which is large as compared to said first longitudinal distance, so that any tendency of bumps encountered by said front wheel means to move said rotary cutter means vertically is reduced in proportion to the ratio of said first longitudinal distance to said second longitudinal distance;

(g) said front wheel means including a front wheel frame having tandem front wheels rotatably mounted thereon;

(h) said front wheel frame being pivotally connected to said frame means for pivotal movement relative thereto about a transverse horizontal axis intermediate said tandem front wheels, so as to further reduce any tendency of bumps encountered by said front wheel means to move said rotary cutter means vertically;

(i) the forwardmost of said front wheels being a steerable wheel and the other being a caster wheel; and

(j) means for steering said steerable wheel.

4. A self-propelled, vehicle-type, pavement-leveling ma- 25 chine as set forth in claim 3, including:

(a) rear main and front extension frames together constituting said frame means and each having front and rear ends;

(b) said main frame having said rotary cutter means and said rear wheel assembly mounted thereon ad jacent its said front and rear ends, respectively;

(c) said extension frame having said front wheel means mounted thereon adjacent its said front end;

(d) means pivotally connecting said rear end of said extension frame to said main frame, intermediate said front and rear ends of said main frame, for relative pivotal movement about a transverse horizontal axis; and

(e) abutting stop means on said front end of said main 40 frame and on said extension frame for supporting said front end of said main frame on said extension frame.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 3 Italy.

CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner. 

1. IN A SELF-PROPELLED, VEHICLE-TYPE, PAVEMENT-LEVELING MACHINE, THE COMBINATION OF: (A) A FRAME MEANS HAVING LONGITUDINALLY SPACED FRONT AND REAR ENDS; (B) FRONT WHEEL MEANS CONNECTED TO AND SUPPORTING SAID FRAME MEANS ADJACENT SAID FRONT END THEREOF; (C) REAR WHEEL MEANS CONNECTED TO AND SUPPORTING SAID FRAME MEANS ADJACENT SAID REAR END THEREOF; (D) ROTARY CUTTER MEANS MOUNTED ON SAID FRAME MEANS INTERMEDIATE SAID FRONT WHEEL MEANS AND SAID REAR WHEEL MEANS, AND ROTATABLE ABOUT A HORIZONTAL AXIS EXTENDING TRANSVERSELY OF SAID FRAME MEANS, FOR LEVELING PAVEMENT OVER WHICH THE MACHINE RUNS; (E) MEANS ON SAID FRAME MEANS AND CONNECTED TO SAID ROTARY CUTTER MEANS AND SAID REAR WHEEL MEANS FOR DRIVING SAID ROTARY CUTTER MEANS AND SAID REAR WHEEL MEANS; (F) SAID ROTARY CUTTER MEANS BEING SPACED FORWARDLY FROM SAID REAR WHEEL MEANS A FIRST LONGITUDINAL DISTANCE, AND SAID FRONT WHEEL MEANS BEING SPACED FORWARDLY FROM SAID ROTARY CUTTER MEANS A SECOND LONGITUDINAL DISTANCE WHICH IS LARGE AS COMPARED TO SAID FIRST LONGITUDINAL DISTANCE, SO THAT ANY TENDENCY OF BUMPS ENCOUNTERED BY SAID FRONT WHEEL MEANS TO MOVE SAID ROTARY CUTTER MEANS VERTICALLY IS REDUCED IN PROPORTION TO THE RATIO OF SAID FIRST LONGITUDINAL DISTANCE TO SAID SECOND LONGITUDINAL DISTANCE; (G) SAID FRONT WHEEL MEANS INCLUDING A FRONT WHEEL FRAME HAVING TANDEM FRONT WHEELS ROTATABLY MOUNTED THEREON; AND (H) SAID FRONT WHEEL FRAME BEING PIVOTALLY CONNECTED TO SAID FRAME MEANS FOR PIVOTAL MOVEMENT RELATIVE THERETO ABOUT A TRANSVERSE HORIZONTAL AXIS INTERMEDIATE SAID TANDEM FRONT WHEELS, SO AS TO FURTHER REDUCE ANY TENDENCY OF BUMPS ENCOUNTERED BY SAID FRONT WHEEL MEANS TO MOVE SAID ROTARY CUTTER MEANS VERTICALLY. 